Spray Pattern Systems - from Oxford
Lasers produce high speed movies and perform fully automatic spray pattern analysis / characterization:
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Measurements: Spray Pattern, cone angle / plume geometry and duration of spraying events.
A wide variety of sprays and aerosols (e.g.
metered dose inhalers, nasal sprays, fuel injectors) need
characterization. Typically analysis of
cone angle / plume geometry, pattern, ellipticity, duration, time history,
density etc is required. Often analysis
of drop / droplet size and velocity is also required.
Oxford Lasers has developed a number of
techniques for aerosol characterization that allow measurement of all these
parameters using image analysis.
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Cone angle / Plume Geometry Measurement
For cone angle / plume geometry analysis of
an aerosol a laser lightsheet slices through the plume and a high speed movie
is taken. Images from the movie are
combined and the angle / geometry measured.
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A sample composite image is shown above for a metered dose inhaler with cone angle marked
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Spray Pattern / Ellipticity Measurement
For ellipticity / pattern characterization the laser lightsheet is repositioned and again
a high speed movie is taken.
Images of the aerosol plume are combined and an ellipse is fitted to the resulting image
providing a measurement pattern.
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A sample composite image, with fitted ellipse marked, is shown.
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Applications
Characterizations of:
- Pharmaceutical devices in R & D and for FDA (nasal sprays, MDIs)
- Domestic aerosols (deodorants, hair sprays etc...)
- Fuel Injectors
- Paint application
- Pesticide application
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Elimination of Motion Blur
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An aerosol plume is often moving at high
speed. With conventional lighting motion
blur would be a problem. Oxford Lasers
uses pulsed lasers to completely
eliminate motion blur (see image above). A major additional benefit of using pulsed
lasers is that simple additions
to the technique allow measurement of velocity (PIV)
and droplet size (VisiSizer). Envision Systems
can be upgraded to provide velocity and droplet size data.
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- Fully configurable via a unique tree structure
- Easy to use - read and save the analysis procedure
- Can be fully automated so that no user judgement is required for quality control applications.
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Nodes Supported:
- Importation for image aquisition
- Dewarping: removes image distortion
- Merge images: combines images from a high speed movie
- Plume geometry: Automatic cone angle measurement
- Ellipse fit
- Size & Shape of pattern
- Plume Width & Height
- Intensity integration: used for duration measurement, and mass-flow estimates
- Collate and report results
- Subtract a single image: remove unwanted features appearing in all images
- Also: Image marking, time and space calibration (two types), export, import
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